Abstract—TCP being the most widely used routing protocol for wired network considers packet loss as an indicator of congestion and calculates its congestion window according to that, but this approach is not suitable for wireless network where packet loss occurs due to various reasons other than congestion. Taking into consideration heterogeneous network, in this paper we explore a new variant of TCP, which has only sender side modification, end-to-end reliability and dynamic window calculation technique, which gives better result compared to existing known variants of TCP. We call it TCP Rcc. Here, we have used fixed window concept because it proves to produce better result.